In a bowl, combine the eggs, sugar, oil and vanilla; mix well. Combine flour, baking powder, cinnamon, baking soda and salt; stir into the egg mixture just until moistened. Toss pears with lemon juice. Stir pears and walnuts into batter (batter will be thick).
Spoon into two greased 9-by-5-inch loaf pans. Bake at 350 degrees for 55 to 60 minutes or until a toothpick inserted near the center comes out clean. Cool for 10 minutes before removing from pans to wire racks.